Most commercial footwear are designed and manufactured on a curved shoe-last, although the amount of curvature of the shoe-last and the turning point of the shoe-last centerline have not been well defined. This longitudinal shoe-last curvature or so called “flare” is a critical design feature for a shoe since it has to be compatible with the wearer's foot curvature in order to produce the right fit and comfort. Foot flare has been defined in several different ways, and each definition is based on a different measurement. Foot flare angle defined by Yavatkar (1993), involves angular measurement, which is itself specified according to different reference points and is the same for a last as well. As shown in FIG. 1 the flare angle β is measured from the reference heel centerline HL to the toe centerline HM. The heel centerline HL is obtained by joining the two center points of the lines located 10 mm and 50 mm from the pternion H. The points B and C correspond to the first and fifth toe projections and the toe centerline HM is obtained by joining the pternion H and the toe center M where BM=MC.
Another measurement for curvature is a foot flare ratio defined by Freedman et al. (1946), which utilizes the ratio between the perpendicular distance to the medial side of the first metatarsal (distance a) and the perpendicular distance to the lateral side of the fifth metatarsal (distance b) from the heel centerline HL (FIG. 1). The foot flare ratio is defined as a/(a+b).
Based on either of these definitions, the flare on a foot and a shoe-last can be determined. However, there is no such device available for such a measurement. There are many foot and shoe-last measuring devices such as the brannock, ritz stick, foot fitter, etc readily available in the market but all of them measure only linear dimensions. The present invention at least in its preferred forms allows a number of linear dimensions to be measured in addition to the flare angle.